What is CVE-2011-2669?

CVE-2011-2669 is a medium-severity vulnerability in Mozilla Firefox, classified under Improper Certificate Validation. CVSS score: 6.5/10. Published 2020-01-21.

How severe is CVE-2011-2669?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Vulnerability in Mozilla Firefox

CVE-2011-2669

Mozilla Firefox prior to 3.6 has a DoS vulnerability due to an issue in the validation of certificates.

Vulnerability class: Improper Certificate Validation

Published 2020-01-21 · last modified 2026-06-16.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.006 (44.5th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 45th percentile — 44.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000

Affected products

Mozilla Firefox — versions prior to 3.6

Weakness classification (CWE)

CWE-295 — Improper Certificate Validation

References

jvn.jp/en/jp/JVN70984231/index.html (Third Party Advisory)

Frequently asked questions

What is CVE-2011-2669?: CVE-2011-2669 is a medium-severity vulnerability in Mozilla Firefox, classified under Improper Certificate Validation. CVSS score: 6.5/10. Published 2020-01-21.
How severe is CVE-2011-2669?: Medium severity. CVSS v3 base score is 6.5 out of 10.